issue 6401 - 6661 satisfaction by Notification wsdl approach

Bob,

We attach the summary of satisfaction of  issue 6401-6661 ( approach A)
with this email to provide information towards a closure of this issue
at F2F meeting. 

To provide some background, two approaches are proposed to address issue
6401 -6661:

Approach A (Ours): It is based on the notification wsdls and (optional)
ws-policy assertions to link the operations of the event sink with the
events of the event source. 

Approach B (Gill): It is based on customized NotificationDescription
(ND) xml dialect for subscriber to fetch and generate event sink wsdl.

The main difference between these two approaches is:  approach A is
based on wsdl and approach B is based on customized xml dialect ND for
wsdl generation. ND is a simplified version of wsdl and anything
expressible by ND should be expressible by wsdl. 

However, as a non-standard private xml dialect, here are some
issues/differences with ND  based approach B comparing to the wsdl based
approach A. 

1. As a non-standard xml dialect, it requires extra processing
steps/procedures to transform ND into wsdl before the service can be
used and implemented. And this process is private to WS-Eventing and not
in any other WS-* standards.

2. It is new knowledge beyond wsdl 1.1/2.0 specifications with a
non-standard data type.

3. Most policies are attached to the WSDL subjects (endpoint, message,
operation and service) and they will not be available to ND anymore.

4. The ND does not support other MEPs (message exchange patterns) in
WSDL 1.1 and 2.0 except outbound, whereas wsdl based approach (approach
A) can supports     them out-of-the-box.

5. It requires tools and developers to familiarize with a new XML
dialect and its ND semantics, whereas in approach A, both WSDL and
optionally WS-Policy are well defined and widely used by the Industry
and other WS-* standards.

Many thanks,

- Wu Chou/Li Li